Loading machine



N. D. LEVIN LOADING MACHINE Jan. 2, 1945.

original Filed oci. 22, 1957 2 Sheets-Sheet 1 /NvE/vTo/Q Nui D. L'Evm,

Jan. 2, 1945. N. D.y LEVIN 2,366,536

y LOADING MACHINE Original Filed Oct. 22, 1937 2 SheetsfSheet 2 NILS D. LEVJN,

HTTQ

"machine embodying `my improvements;`

i in elevation in Fig. *lgand a Fig. 3 is' an enlarged sectional elevation taken on the line 3-3 of Fig. 2, looking inthe direc- Patented Jan. 2, 1945 `LoiiDINGf MACHINE NilsDfLevin, Columbus,lhio, assigner to The` Jeffrey Manufacturing" Company, `a corporation of Ohio :original imputation octobefzz, 1937, serial No. 170,426. `Divided and this application Septemher\z`2, 1943, seraia1No. 503,407

"` This invention relates toloading machinesand o ne of the objects ofthe invention is the provision lof improved hydraulic mechanism for adjustirrg theelevationfof a conveyor swingable on "a horizontal axis and resiliently supporting such conveyor when infadjusted position.

a `Other objects of the invention will appear hereinafter, thefnovel features and combinations beingset forth' in the appended claims.`

` In the accompanying drawings, ff

Fig. 1 is a sideelevational view of the loadn Fig. 2 is a vertical longitudinal sectionalview ofthe rear portion of the loadingr machine shown tion of `the arrows. a 2 l i p This application is adivision of `my abandoned applications. N.`1'1o,426,n1ed oct. 22 iovfo-i an Improvementin aloadingmachine.

The loading machineillustratedin Fig.` 1 of `the accompanying drawings comprises a track mounted truck 40 upon vwhich ismounted a gath-, ering conveyor`4l and a discharge conveyor 42,'

the former being adapted to dig into and gather loose or semi-compact coal -and to convey it to the latter by' which it is discharged into track mounted `coal cars, one of whichis illustrated: c y

` "3Q'preferablyfalwaysidrivenn in the same'direction so 'as lto drive the conveyors through thepo-wer i Power meansis` providedfto'tramthe loading machine along the mine tracks at a relatively fast speed, and tooperate it along said tracks at `a feeding or' operating speedfwhile at the` samea `time operating the gathering and discharge con-""jA veyorslto4 gatherand load coal into coal cars 43.

The truck 40 comprisesforward` flanged wheels 5| for engaging `the mine track 66 and also rear `flangedwheels 56 for engaging the track 66. The gathering conveyor unit 4 is pivotally connected at 82 to a supplemental frame 18, forupanddown swinging adjustment` by means of thehydraulic motor |02 on which the` boom 83 is resiliently mounted.` The hydraulic motor |02 is mounted i on` the forwardendjof the supplemental frame' 18 and acts to adjust the elevationof the front;

end of the conveyor 4|.T'I'hegathering Vco'nveyor `unit 4| is also swingable laterally'to Various angular positions` relative `-to the truck` 40,

springs |26 one ofiwhich is'shown in Eig. 1. When the loadingmachine,` with thegathering conveyor` l Y unit 4| elevated,` travelslalongthelmine track Bsp-cipal piston }|99,provided at its `top wltha clamped about the same weig'ntis carried on each of the axles of the wheels 5| and 56. When at the coal face, theA iront end of` the A'gathering conveyor Vunit 4| is lowered until it rests on the mine bot-l tom. `This takes a great amountoi weight ofi the front axle and, except for springs |216, |26, would throw the machine out of balance to such i an extent that theffront wheels `5I might raise off the track and derail the machine. l Also, sometimes the front end of the gathering conveyorll i climbs up .a roll in the mine bottom. T-hesprings |26, |26 insure sufficient load on front wheels "5|,`5| to keep them on`the` track rails under all normal conditions and` prevent derailment.` "The discharge` conveyor unit 42 extends rearwardly from the hopper |55 into which gathered material is delivered by the'gathering conveyor unit 4|. endless` chain flight conveyor |65 transfers the material in the hopper |55 to the mine c`ars43.`

The Ibed plate 5U is attached rigidly `to the truck frame `and extends rearwardly of the rear Wheels 56. This bed plate 50 supports the single.

drive motor `224 which operates all the apparatus on the loading machine including the mechanism for driving the endless traveling conveyors of the gathering unit 4I and the endless." chain flight conveyor' |65 ofthe discharge unit 42. L

The electric'motor 224, although reversiblejis transmission `mechanism shown" in Fig; 2, always in the same direction.` Truck 'propelling mechal fnism as shown in detail insaid'co-pendingjapplication, SNN. 170,426 iiand also iin another coi. pending application, S. 379,475, iiledilf'eb. 18, 1941, as a division of- S.' N. -l 170,426), :is provided to reciprocate the entire loading machine along the mine track 66 'during loading operations.

As shown in Fig,` 2, the discharge conveyor unit '42 is dividedinto sections', one being a hopper sectionk|58 which is mounted in xed relation l to the truck 46 and the other section being a discharge boom` |69 which is pivoted at |68 for Interposed between the bracket |95 and the rear end of the bed plate is a single acting hydraulic piston motor device |94; f f

i 7 Pivotally connectedto the. transverse bracket |95 on a horizontal axis is a cylinder |96 .hav-

i inga head |91 providedwith an'appropriate inlet port N| 98 Vwithin which cylinder extends a cylindrirod 204 which extends into the coil spring 202.

and .into the Lguide cylinder e201, the coupling member 2 U3-being pivotally attachedto a bracket 205 formed integral with the rear bed plate 50 and the bumper `plate 41 of the truck 40. i

It is evident that the coil spring 202 willltoro-` vide a flexible support for the disch'arge boom |69 for any position of adjustment thereof, thus relieving any strain caused by :a large lumpofy coal on the boom striking the top of the mine roof or for any other similar cause.` The guide rod 204 provides a guide andretaining means for the coil spring 202. l

It will be evident that by admitting uid u der pressure from pipe 219 to the port I 98 vordis- .charging it by said portthe piston |99 may -be ,adjusted in the cylinder |96 to expand orcontract the hydraulic piston motor mechanism |94 thus swinging the discharge boom `|69 about the -By l horizontal axis provided by the pins |68. locking the `iiuid in thecylinder |96, as `herein :rafter described, ythe -boom \|69 may be locked in ,any elevated position. y i

As shown in Fig. 2, the electric motor 224 lis mounted upon .therear bed plate `50 of the truck` 40 and compactly positioned below the .discharge conveyor 42 `which extends upwardly andrear- 'wardly from the -hopper |55. Dueto this positioning of the electric motor 224it'is possible to provide a very large and powerful motor which is capable of effecting any and all .of the drives .required at any 'time while maintaining a machine -of low `height to permit `its `use in a relatively (low Vhead coal mine. Said electric motor 224 is provided with a. forwardly extendingar mature sha-ft A225 carrying a drive 4pinion 226 Ameshing with a bevel ring gear 221 `which is rigidly attached to the housing 228 -of a friction .clutch mechanism 229. The housing .228 is keyed lto a vertical shaft ,23,0 `which is mounted at its i top in a bracket 232| rigidly attached :to the vmain frame of the truck 4.0, there being an anti-'friction ball .bearing 232 :interposed between the 'bracket 23| and the shaft 230 which 4is held in place by a removable cap 23:3. The bottom of the :shaft 230 'is supported in a bracket formed rigid with the bottom `plate 50, said support ,being through an anti-friction ball .bearing 235. Keyed lto :the lower end of the shaft 230 and above the :bearing 235, is a bevel gear i236. It may thus be inoted .that the lgear -221 :and the gear 236 being both keyed to the shaft 230, will tbe driven together at .all times from the motor 224;'

J ournaled loosely on the central portion of the shaft 230 is a clutch member 231. Splined on the interiorof the housing 228 and on the exterior of the clutch member 231, which membersV 228 and 231 comprise co-operating clutch members, is a plurality of overlapping stacked friction :plates 238, alternate ones of which are connected to the housing v228 and the clutch mem- `ber 231, respectively. AAdjacent its bottom the clutch member 231 is provided with an integral .extended flange to which is pinned a gear 240.

The flange, in addition to supporting the gear `240, also acts as one compression member for the friction clutch plates 238. i

To effect a compression of the clutch plates pression ring within the housing 228 having a flange which bears against said plates 238.

Downward movement of the ring to effect the aforementioned compressing action is effected by a plurality of pins 242 which extend through apertures in the housing 228 and are carried by a yring operable 'through yan tantifriction '.ball bearing `by atrunnion collar which is controlled by a shipper 246 keyed on a shaft 241 (Fig. 2).

It will be evident that rocking movement of .the shaft 241 to urge the collar downward will cause 'an application of the friction clutch 229 to drive thegear 240 and when the shaft 241 is` i.

"released the `clutch 229 will automatically be- 238 and thus to effect an engagement of the come disengaged due to lack of sufficient clamping pressure on `the -plates 238.

It Vmay be zstated that the gear 240 which is Icontrolled` by the clutch '229 is individual to a geartrain comprising the gears 25| and 254, fol` driving the gathering conveyor, as more fully `explained in my lcopending application, S. N. 379,475. The hydraulic motormeans for swing;v

ing the `gathering conveyor -unit `4I on the up- .right axis fof `the shaft .255 isalso v`disclosed yin said During normal operation, the lconveyor boom 83 rests on thesprings v| 26, kwhile'the front wheels 5| are .on the mine track. 'When the gathering conveyor Vis l`adjusted in elevation the hydraulic motor |02 acts through the spring-S426 on the `bottom plate of the boom'83, but whenV theupward movement of the gathering conveyor is resisted yby dislodged coal .fallen vfrom the Semi- `compactmass onto the receivingendl-of the gathering unit 4|, the springs |26 imaybecompletely `compressed to afforda direct connection between 40 thevmotor 10:2 and the boom 83 therebyeffecting a powerful and positive lifting -of the`freceiving fend of the gatheringunit v'from the mass of dis-- lodged coal. At the `same time rthe truck propelling mechanism may be reversed to effect lwithdrawal ofthe gathering unit Ifrom such mass Vof dislodged coal. v i

It shouldbe particularly noted that a single electric motor 224 is provided `for operating the entire loading machine including the operation of a hydraulic pumpto provide hydraulic presi sure to the hydraulic control system for the motors |02, |94.and the hydraulic motor for swinging the gathering conveyor unit 4| on the upright Vpivot 255. These hydraulic `motors may be .controlled individually by the operator located ata single station at one side of the loading ma chine. By means lof one vvalve the operator may control thedouble acting hydraulic motor |02 `to effect adjustment in elevation of the gathering conveyor unit 4l and the locking thereof in any ofthe adjusted positions shown in full and dotted lines at the right-hand end of Fig. 1.r By means of another valve the operator may effect adjustl ment of conveyor unit 42 by means ofthe single acting Vertical reciprocating hydraulic motor |94 on the horizontal axis of the pivot at |88, to the full and dotted line positionsV shown at the left- 4hand end of Fig. l. yWhenthe gathering` conveyor unit 4| is in the full line position shown in Fig. 1, the Wholev machine may be transported along the mine track under the control of1 the operator who may start or stop the electric motor 224by means of motor controlling apparatus. By-means of a reversing switch the operator may reverse the electric motor `224 and. thereby con trol the directions of travel of the conveyor chains of the gathering unit4| and the dischargeunit 42. l l

The' truck propelling means comprisespower` Reverting to thejsingle acting reciprocatin transmission mechanism between the electric '5 motor 224 and all of the wheels `5| and SEofthe truck: This power transmission mechanism is under the control of the clutch229 in Fig. 2. The

i operator `may applyor release the clutch 229 by rocking the shaft `241. The truck propelling power transmission `mechanismalso includes `two reversing clutches, either of which may be applied by the operator and consequently the; loading machine `duringoperation may be movedi along l themine track in Yeither direction without re-` versing'theelectric motor 224. o

It will thus be seen that the electric motor` 224 may be operatedcontinuously in the same direction, while bymeans of said reversing clutches thegathering mechanism may be moved forwardly or rearwardlyv under the control of theoper-` ator. Ayvery powerful sumping movementj` of the gathering unit 4I into the semi-compact `mass of shot down coalmay thus be effected andwhen- Y ever desired a very powerful withdrawal move- `thereby causing the conveyor flights to release the contacted coal and relieve the overload.

The discharge conveyor unit 42 may comprise two sections |10 and |1|, with therear `section |1| `movable laterally `on the upright pivot Hydraulic motor mechanism is 'controlled by a hydraulic motor |94, attention is called to the enlarged view `in Fig. 3 which is a `sectional elevation on the line 3-3 of Fig. 2 looking in the dil rection ci. thearrows. As shown in Fig. 3, the

coupling member 203 at the lower end of the f guide rod 204 is pivoted by means of the pivot pin` 201 tothe angles 206, 206 which are rigidly secured to the bracket 205 which may be inthe formoffa cross-piece detachablysecured to the rear end of the bed plate by means of bolts one of which is shown at 208 in Fig. 2.`

As shown in Fig. 3, the piston |99 is provided with a tubular extension 209 which is open at its lower end. This tubular extension is provided with aninner annular flange 2|0 near its upper end ,and with another annular flange 2|| 'at its lower end. These annularflanges 2|0, 2li have the same diameters, each equal to the outer diameter of the guide cylinder 20|. i

`Theilanges 2|0, 2|| `receive the guide cylinder 20|` and the spring 202 presses against the innerupper closed end 2|2 of the cylinder to hold the same against the bottom of the piston 99.

The upper side of the' piston |99 is provided with a screw-threaded extension 2|3 to receive anut2|.4 `for clamping the washer2|5` against the sealingring 200 `tohold the latter in place.

In front of an opening 2 I6 in the bumper plate 41 isa pair of spaced-apart hooks 2|1, 2|1 rigidly securedto the bracket 205 andadapted to have anchoredf thereto a towing rope or other coupling means extending to a mine car or to a hauling `mine locomotive. In other words, the hooks .2|1, 2|1may serve to connect the loading machine to mine cars so that the latter :may be valve at the operators station `to eii'ect powen 4 transported in the mine if the loading machine swinging of the rear section |1| of the discharge conveyor. v l

It is preferred that a main operator should be in a position to operate all of the valve control- `ling levers and that another operator` should. be

able by means of extended actuating connections,

i to control adjustments of the discharge conveyor l `'self-propelling means of the loader for transporering conveyor toprevent overflow from hopper f `Whenever the electric motor 224 is operating, the hydraulic pump is being continuously operated so that at all times the hydraulic system is ".50

time a by-pass valve is automatically `moved to `no-load position. The high pressure valve opens only when the` maximum output of pressure' is exceeded but when the valve is opened,` avery free passageway is provided for by-passing the transverse perforations 22|.

tation purposes, amine locomotive may be coupled to the hooks 2|11and suchlocomotive relied on to move the loader from one place to another in the mine. i Notionly is the lower end ofthe reciprocating hydraulic motor |94 pivotally connected at 2 01 to the rear end of thebed plate 50 and therefore `to the rear end of the `truck frame, but the upper end of such hydraulic motor is also provided with means for pivotal connection to the transverse bracket which is rigidly connected to the bottom plate |12 ofthe discharge boom |69. i

As shownin Figs. 2 and 3, the upper closure head I9110f the cylinder |96` is provided with a pivot pin"2|8 extending through the angles 2|9 which are rigidly `secured to the transverse bracket |95.` The pivot pin 2|8 may `be held in place by means of cotter pins inserted through the In a smiliarmanner the pivot pin 291 may be kept fromdropping out by means oi cotter pins inserted through `the transverse perforations 222.

` it should be particularly noted that theupper Y and lower pivot pins 2|8` and 201are in parallelism` with each other and each extends transversely of the loading machine so thatwhen the hydraulic motor |94 isexpanded and contracted to adjust the elevation of the rearendof the `dis-- `charge conveyor unit l|2y the piston |99 will always belfree to move in the cylinder |99 without binding. Such free movement o the piston |99 in the cylinder |95 is also facilitated by telescop-` Aing thepiston |99 and its extension 209 into the 'top of the limit stop rod 204. There will then be be expanded and contracted to adjust the elevaunit 42. ported by the spiral spring 202 irrespective of the Vveyor unit 42 and abnormal loadsare positively cylinder: Illv so that the guiding action of'. the piston in the cylinder extends over 'a wide ,cy-line drical area. At the same time, the spring202 always extends into-the guide cylinderV or inverted cup r| over almost itsv entire length so that at all times the weight of the discharge boom |69 and the load' thereon, is carried-by this spring, the latter and the hydraulic motor |94 beingalways in series between the bed plate 50 and the plate |12, irrespective of the adjusted; elevation l of the rear end of the discharge conveyor unit 42.

It should also b'e noted that the upwardly projecting guide rod 204 may serveas a limit stop to protect thelower end of the guide cylinder 20| andthe lower flange `2|| of the piston extension Y 2.09, against; striking against the angles 206, 206. It the discharge conveyor unit should become overloaded ythe spring 2102 would bel compressed until the up-per end of the rod 2 04 engaged the inverted bottom 2|2 of the guide cuporcylinder 20| thereby limiting the `extent of downward movement of the cylinder 20| and of the ange 2| The upper end of the coupling member 203 may be circular and of the same diameter as the washer 220 thereon and each of' less diameter than the inner diameter of the cylinder 20| so that when the spring 202 is compressed to the n extent permitted by the limit stop rod 204,' the lower end 'of the cylinder 20|.will telescope over thewasher 220 and the upper end of the coupling Amember 203 without .reaching the langles 206, 206.

The lower side of the cylinder head |91 is providedwith a recess v223 for receiving the nut 2|4, thereby increasing the length of. stroke of the piston |99. When thereis no hydraulic pressure in the chamber 224, the cylinder head |91v may rest on the piston |99 or 4the screw-threaded extension 2|3. `The discharge conveyor and its load will then be carried by the spring 202. Wit-h normal loads on the discharge conveyor, the hyt draulic motor |94 may be. expanded and contracted, and the discharge conveyor and its load would still be carried bythe spring 202. With overloads onthe discharge conveyor unit 42 the spring 202 will be compressed to its maximum extent and then the discharge Vconveyor and its load would be carried on the limit stop rod 204. But whether the discharge conveyor unit 42 and its load is carried by the spring`202 or by the rod 204, the hydraulic motor may-'al'- waysbe expanded and contracted to adjust the elevation of the rear end of the discharge conveyor. l

When the cylinder 96 is at is'lowermost limit of travel,l the upper end of the screw-threaded extension 2|3 will abut against the ceiling of the recess 223 and at such time the inverted bottom 2 l2 of the guide cylinder 20| will rest against the a rigid sup-porting connection, entirely mechanical, between the discharge boom |69 and the rear 4,end of the truck frame but in such event the spring 202 is still in series with the hydraulic motor |911, with the spring 202 under maximum compression` ready to `expand again as soon as the load, on the Adischarge conveyor is suniciently reduced. l Even when Athe spring 202.is under maximumy compression the hydraulic motor |94 may .-7 tion of the rear end of the discharge conveyor Normal loads are therefore alwayssupelevation of the rear end of the discharge conn .aeeasae resisted and supported when necessary te prevent breakage of any mEQhaniSm.

The vspring 202 is preferably rela-,tively large dischargeboom |69` and its load but also to abe' sorb the shocks due to. the largest lumps of coal suddenly engaging the roof of the mine chain.- ber while being conveyed to. mine cars. The .spring 202 ts loosely in the cylinder 20| and also fits loosely over the guide rod 204 as shown in 3, so that free compression of thespring may be secured without binding. Nevertheless, the axes of the rod 204, spring 202 and cylinder 20|` substantially coincide at all times during compression and expansion, ofthe'V spring 2,02, thereby maintaining the guiding action oflhe rod204 tp facilitate freemovement ofthe piston- |99 inthe hydraulic cylinder |946 and thuslseepingthe axis of the latter always in position to coincide withv the aforesaid axes ofthe rod 204, spring 202 Aand cylinder 20|. In other words, not only `arethe spring 202 and hydraulic cylinder |96 always in series, but the axis of thespring `2|)2falways cof illcgides substantially with the axis of thepiston various changes in the details and arrangement of parts withoutv departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore wish not to be restricted to the precise construction hereindis.- closed. j

Havingthus described and shown an embodiment of my invention, whatI desire to secure by Letters Patent of the United States is:4

l. A loading machine comprising the combination with a supportingframe, of a conveyor mounted on said supporting frame for swinging movement relativelytliereto on a horizontal` axis,` an elongated reciprocating, hydraulic piston motor comprisinga cylinder open at. one end and an elongated piston projecting from ysuchopen end, a spiral cushioning spring connected to the piston of said motor, mechanism connecting said motor and said spring in series to constitute an expansiblej resilient supporting unit, a. .pivotal connection between one end of said unit and said conveyor, andan additional pivotal connection between the other end of said unit and said frame, the construction` andarrangernent being such that said spring is able to resiliently'sup` port the conveyor for pivotedrmovvement on said horizontal axis relatively to. said supporting frame in any position to which the motor mal be adjusted. 2. A loading machine comprising the conibination with a supporting frame, of a conveyor mounted thereon for adjustment relative there- `fluid pressure cylinder, ,a fluid pressure. chamber ybeing thus formed above said piston, cushioning mechanism pivoted lat its lower end, to said vsupporting frame and comprisinga spring QX- tending upwardly into said cylindrical piston,

and means for controlling the flow'of fluid pres- -sure medium into and out of said fluidy pressure chamber to eiect adjustment in elevation of said conveyor relative to said'frame.

` 3. A loading machine comprising the combination with a supporting `frame, of a conveyor pivoted thereto, a combined hydraulcjack and cushioning device pivotally connected to said obviously those skilled in the art may makey conveyorandsaid,frame to occupy a position between` `thesame, said device comprising a hydraulic cylinder `pivotallv connected `to said conveyonanda rad pivotally connected to; said framelwith the `rod"-.=xtendingupwardly into a cushioningspring and the latter `extending upwardly` into a cylindrical piston located in said `hydraulic cylinder, `and a hydraulic connection to said hydraulic cylinder above the `upper `end of said piston, the construction and arrangement beingsuch' that byintroducing liquid into said hydraulic cylinder andwithdrawing liquid from said hydrauliccylinder the Yelevation ofthe conveyor may `be adjusted while said spring cushions the vweight of ,the` conveyor and the variable load thereon during operation thereof.

4. .A loading machine` comprising the `combination with` a supporting frame, of a conveyor.

mounted thereon `for adjustment relative thereto on a horizontal axis, a combined fluid-pressure motor and cushioning device pivotally connected at its ends tosaid frame and said conveyor, said device comprising a cylindrical piston extending into a uid pressure cylinder forming a fluid mounted thereon for adjustment relative thereto oniahorizontal axis and extending therefrom,`

a reciprocating hydraulic motor comprising a cylinderlopen` atone end with an elongated pis- ,iton therein and` projecting therefrom, resilient supporting means connected in series with said hydraulic motor to constitute an expansible resilient supporting unit, said resilient supporting means `comprising `an elongated helical spring extending into said piston, a pivotal connection between the upper end of said unit and said conveyor, and another pivotal connection between the lower end of said unit and said supporting frame, the construction and arrangement `being such that at whateverelevation the hydraulic `motor holds the conveyor relative to theiframe the said hydraulic `motor `and said resilient supporting means shall remain in series so that the conveyor and its load shall always be carried by said resilient supporting means. l

d `8. In a loading machine, the combination with a supporting frame, `of an elongated `conveyor pivoted to saidsupporting `frame for adjustment about a horizontal axis and extending from said frame, an elongated hydraulic `motor` comprising a cylinder open at one end with an elongated openendedpistcn thereinand projecting therefrom, `resilient supporting means connected to one end of said hydraulic motor to form a suping into said open ended piston, and means Y pivotally connecting the ends of` such supportaxis, a reciprocating hydraulic motor compris-3 ing a cylinder open attoneend with an elongated piston reciprocable therein and projecting from such open end, cushioning spiral spring means,

i mechanism connecting said hydraulic motorand said spiral spring means in` series to constitute an expansible resilient supportingyunit, a pivotal connection between said unit and said conveyor, another pivotal` connection between said unit and said supportingframa and meansfor concations of said pistonirelatively tosaid cylinder and the locking of the hydraulic motor at adjusted length whereupon said spiral spring means yieldingly supports said` conveyor for `limited swinging movement on said horizontal transverse axis. i l

.6. Ina loading machine, the combination with a supporting frame, ,of` a conveyor, mounted on said frame for swinging movement about a horizontal axisa hydraulic pistonimotor compris-- ing a cylinder open `at one end with lan, elongated pistontherein and projecting therefrom, spiral spring `mechanism, extending into said elongated piston and connected in series with said hydraulic `motor to constitute an expansible 'supporting unit, a pivotal connection between one end of said unit and said conveyor, andanotherpivotal connection between the other end of said unit and said supporting frame, the construction and arrangement being such that said spiral spring mechanism-supports the con- `may be adjusted. l

7- In a loading machine, the combination with porting unit, said resilient supporting meansV comprising `an elongated helicalrspring extending unit Ito said supporting frame and said conveyor so thatin all the positions to which said conveyor is adjusted by said hydraulic motor the whole weight of the conveyor and its load may be sustainedby said resilient means and thepivotal connection between said conveyorand said supporting frame. d

9. In a loading machine, the combination with a supporting frame, of an elongated conveyor unit comprising a conveyor frame pivoted to said supporting frame on aihorizontal axis, a fluidipressure motor comprisingan elongated piston in t an open ended cylinder, resilient supportingl `trolling said hydraulic motor to effect reciproon said` supporting frame.

.ing into said piston and projecting therefrom,

a supporting frame, of a conveyor pivotally` mechanism pivoted on `a horizontal transverse axis to one of said frames, said resilient supportingmechanism comprising an elongated helical spring extending Vinto said piston to the bottom thereof, Va pivotal` connection between said iiuid pressure motor and-the other frame, mechanism connecting said `resilient supporting mechanism and said fluid pressure motor in series,I and means for controlling said motor to effect expansion of said fluid pressure motor andthereby adjust said conveyor` frame relative tosaid supporting frame on` said first-named horizontal axis while said resilient supporting mechanism aiords a yielding, support for the conveyor frame `10In a loadingI machine,` the combination with `a supporting `frame,` of a conveyor pivoted thereto for` adjustment relative thereto `on a horizontal axis, a hydraulic motor comprising a `cylinder, and an elongated piston in said cylinder and` projecting, therefrom, `compression spring means connected to said motor inseries therewith to constitute an .expansible resilient l support, said compression spring means extendmechanism connecting said unit between said supporting frame and said conveyor, and an abutment associated with said spring` in position to limit the extent of compression thereof.

lar extension of said piston, a springl in lsaid Y tubular extension, a rod extending into said spring, a pivotal connection between said cylinder and one of said frames, and an additional pivotal connection between said' rod and the other frame. y

12. A loading machine comprising the combination with a wheeledl truck adapted to travel on a mine track ,o`f a discharge conveyor unit pivoted'to said truck on a horizontal axis, a reciprocating fluid pressure motor' depending from saiddischarge conveyor unit and comprising an elongated piston extending into an open ended cylinder, and means for resiliently mounting said fl-'uiolv pressurel motor on said truck, said means comprising an elongated helical spring extending'into said elongated piston to the bottomthereof;

13.. A loading machine comprising the combination With ay supporting frame, of a conveyor comprising a framemounted on said supporting frame for adjustment relative thereto, a combined -uid pressure' motor and cushioning device, said device comprisingfa fluid pressurey cylinder pivotedto one ofl said frames and a cylindrical pistonl extending into said fluid pres- .sure cylinder, said device also comprising cushioning mechanism pivotally connected tothe other frame and including a spring extending' into said cylindrical' piston, and means affording iiovvl `offflfuid pressure medium into and out of thesaidr fluid pressure cylinder for variation of the expansion of said` motor for control of the elevation of the free end of sa-'idf conveyor frame.

1141. A- loading machinev comprising the combination-with a supporting frame, of a conveyor unit pivotedi thereto, a combined hydraulic motor and'r a cushioning device pivotally connected to said'conveyor and pivotally connected to said vframelto occupya position between the same,

said? device comprising a hydraulic cylinder and' a rodi-extending axially into a cushioning spring andthe latter' extending axially intoa cylindrical .piston located inl said hydraulic cylinder, and a hydraulic pressure port .for'ingress and egress of' the'hyd'raulic liquid into and from'said' cylin` der; the 4construction and arrangement being such that-by introducing liquid into said hydraulic cylinder and withdrawing' liquid from said cylinder the elevation of the conveyor may be` adjusted While said spring; cushions the Weight 'ofA the' conveyor and they variable load thereon device comprising ai fluid pressure cylinder With an elongated pisto'nltelescopirig thereinto and anl elongated helical cushioning'spring, said device being mounted between me pivotal; connections to said'rframe and said conveyor`,and means for controlling'the vexpansion. and contraction of thev fluid pressure motor tov effectadjustment ini elevation of saidy conveyor on said 'horizontal axis while said'fcushioning spring cushions' the vibrations of theconveyorv due totransfer-of material thereby during operation thereof.`

\ 16. A loading machine comprising they combination with asupporting frame,- of a conveyor`- mounted thereon for adjustment relative thereto on a horizontal axis, a combined Huid-pressure motor and cushioning device mounted lo'etvveenl saidcon-veyor and said supporting frame, said device comprisingI a fluid pressure motor'and cushioning spring arranged inseries', said motor comprising an elongatedopenended piston telescoping into a cylinder and ladapted to receive said spring, and limit stop mechanism associated with said spring and serving to positively limit the downwardv movement of said conveyor rela-- tively to said supportingframe, said limit stop comprisinga rod extending into said spring andi into said piston'.

1*7. A loading machinecomprising the: combination with a supporting frame, of a con-k veyor mounted thereon',4 a hydraulicipiston motor, a cushioning spring, means connecting said motor andr said spring in'Y series between said conveyor and said frame, and a limit stop'y rod extending into said spring" inpositionto be engaged by the piston of said motori to limit the extent of" compression of saidlI spring. i

18. In a .loading machine, the combination with a nydraulicreciprocating motor comprising acylinder and a. piston tlfierein",v of a support, `a cushioning spring between said piston and said support, a limit s top mounted on said support in position tov be engaged by said piston to limit the extentl of comfr'nfession-ofV said spring', and an additional limit stopfor the other` sideot saidpiston. i

159. In a loading machine, the combination with a hydraulicreciprocating motor comprisinga cylinder and a piston therein; of a support, a cylindrical' extension from said piston and adapted to proiect from one end of said cylinder, a' spring-betweenl said support and' said pistonha rod'extendin'g from said' support into said? spring," andA a tubular* guideffor saidspring located in said piston extension 201 A loading machine comprising' the com bination with a supporting frame, of a"con1veyor` mounted thereon for adjustment relative there"-V lto, a combined hydraulic motor and cushioning! structionand arrangement being suchthat when both of said limit-stops vact as such, positive supporting connections are afforded vbetween theA frame and" the conveyorl with' the` spring under maximum compressiorif.` 

